Dirt Bike Tech: The Ultimate Chain Guide Tool

Jul. 12, 2010 By Rick Sieman
One dead Maico 490, courtesy of a derailed chain.

When you've been around of motorcycles as long as I have, you tend to take things for granted. Example:  I took my 490 Maico out to a vintage motocross race and was looking forward to a perfectly good time. Right before the start of the second moto, I took the bike up and down a nearby access road along the motocross track to clean the motor out. At the third pass, I thought I lost all of the gearbox, as I could not get in any gear.
Rear wheel with chain back on and broken adjuster in place.

A look down at the rear end of the bike told the whole story. The plastic chain guide had snapped cleanly in half and derailed the chain in the process.  In complete disgust, I headed back to the pits, swearing profusely in the process, and sat out the moto when I should have been riding.

A 24 mm wrench was used to loosen the axle nut.  Note the chewed up sprocket and broken adjuster.

Later in the week, I put the bike in the air and remove the offending broken chain guide. I manufactured a new one from aluminum pieces and a skateboard wheel. That ought to do it, I thought.

A tie down was used to prevent the bike from nose-diving on the elevated work stand.

About two weeks later, I was at a practice session at Arizona Cycle Park and was rudely greeted by another tossed chain after only a few laps on the course. Closer inspection showed that the rear wheel was cocked badly in the swingarm, thereby causing the chain to come off of the sprockets.  Result? Another wasted day of riding. The right side chain adjuster had broken off near the bolt. In all my years of racing Maicos, I never had this happen before.

Broken chain adjuster was the culprit.

Back in the garage, I checked out the damage. The chain guide was virtually un-damaged, but the sprocket and backing plate on the hub was chewed up. I ordered a new chain adjuster from Rage Racing and put everything back together when it arrived. As luck would have it, the day I installed the new adjuster, I talked with Vic Krause from SideWinder Racing and mentioned what had happened. He told me that I could have very easily used his new SideWinder Straightaway chain alignment tool and probably could have prevented the problem before it happened.
New adjuster.  Please note that the Maico, and many other vintage bikes, has no adjuster marks.

Throughout the years, I have known that the marks on many chain adjusters have not been accurate. Since the Maico doesn't even have marks on the adjuster, I did like most other riders and merely took a measurement from the swingarm pivot bolt to the center of the rear axle. Like everyone else, I use a handy tape measure.

New adjuster in place.

Axle nut should now be snugged – not tightened – in place.

And, like everyone else, I wasn't exactly critical of the measuring. Looking back in retrospect, I caused my problem. Yep, the broken chain guide on the first racing session and the tossed chain on the practice session was caused by me not lining up the chain properly.

The Straightaway was slipped in place over the chain and lightly locked in place on the sprocket.

The Straightaway showed that our first efforts at lining the chain were badly off.  The rod was clearly pointing to the left.

A few days later, my chain guide adjusting tool arrived. Directions were minimal, as Vic said, so just test this product, as only a few were out in circulation at this point. I followed the instructions closely, and much to my surprise the chain alignment that I thought I had completed was not really lined up at all. There I was a potential victim of my own bad mechanics and maybe another day of riding ruined.

The chain was adjusted via and adjuster bolts.

Here’s the chain lined up correctly.  As you can see the rod is now lined up correctly.

Using the Sidewinder Straightaway, I was able to get the chain dead-on straight in a matter of minutes, with no nagging doubt.

The adjusters can be snugged down while referring to the Straightaway for alignment.

Why something as simple as this hasn't been around for decades is beyond me. It’s a tool that should be in every tool box. The Straightaway is easy to use, and more importantly, it’s fool proof. It retails for $24.95 and will save you a lot more than that in the aggravation department alone.

One last check and then the axle can be tightened.

There you have it, a perfectly aligned chain.

Sidewinder Racing
601 Sidwell Ct.
St. Charles, IL 60174

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